Question: Express this product in scientific notation: $(7.40\times 10^{-2})\times (9.00\times 10^{-1})$
Explanation: Start by collecting like terms together. $= (7.40\times 9.00) \times (10^{-2}\times 10^{-1})$ When multiplying exponents with the same base, add the powers together. $= 66.6 \times 10^{-2\,+\,-1}$ $= 66.6 \times 10^{-3}$ To write the answer correctly in scientific notation, the first number needs to be between $1$ and $10$ . In this case, we need to move the decimal one position to the left without changing the value of our answer. $ $ We can use the fact that $66.6$ is the same as $6.660 \times 10$ $ = {6.660 \times 10} \times 10^{-3} $ $= 6.660\times 10^{-2}$